After 62 weeks of continuous inflows, Bank of America Merrill Lynch reports that U.S. investment-grade funds reported $860 million in net outflows last week. Since the last weekly outflow of $1.5 billion in October 2011, high-grade bond funds have grown by almost $180bn, with $165bn of that coming in 2012.

Even with these high inflows, high-grade bond funds are in the middle of the pack compared to other asset classes in terms of percentage change in net assets this year, BofA says. U.S high grade fund asset changes measure 12% year to date, while the top performer is non-US high yield, which has added 36% in net assets this year.

Investors are demonstrating waning enthusiasm for debt that’s had annualized return of 11.7 percent since 2008 and that’s now at about the greatest risk of losing value if interest ratesrise in 19 years. Dollar-denominated investment- grade bonds are losing value for a second consecutive month after yields on the notes dropped to an unprecedented 2.73 percent on Nov. 8, Bank of America Merrill Lynch index data show.

“We expect USD investment-grade credit to struggle to break even in 2013 on a total-return basis,” Richard Salditt, a Deutsche Bank AG credit strategist in New York, wrote in a Dec. 14 report.